Some great advice from
@viditb on translating an iPhone Duo app to a normal iPhone form factor:
"It’s more difficult to go from something that’s bigger to a smaller screen, because now you have to think about the position. Versus if you start from the small screen, it becomes easier. You can think about, okay, this is how I expand the interface.
Think about how you would use the app with the Duo screen closed. Even with Duo, I was conscious about having all the functionality available if you did not want to participate in the gimmick of opening up and closing. So, there is a way to actually eject the tape from the outer screen as well. You press the eject button and it shows up a cover flow. And of course, it’s less fun, but just building in that functionality helped me transfer it to the normal iPhone."